Dexamethasone iontophoresis

Behar-Cohen, F.F., et al. 1997. Iontophoresis of dexamethasone in the treatment of endotoxin-induced-uveitis in rats. Exp Eye Res 65 533. 

A polyacrylic-porous hydrogel saturated with gentamicin or dexamethasone solutions for transcorneal and transscleral iontophoresis has been reported [56 59]. A battery-operated portable device that applies a variable electrical current up to 1 mA, for preset periods of time is used (Figure 26.8). Hydrogels are prepared by radical polymerization of an aqueous... 

Steroids are poorly investigated for the transcorneal route despite the fact that dexametha-sone seems to have a much higher corneal penetration than the positively charged antibiotics after corneal iontophoresis. Eljarrat-Binstock et al. [56] used dexamethasone phosphate-loaded hydrogels for the iontophoretic delivery, applying only 5.1 mA/cm2 current for 1 and 4 min. Enormous amounts of dexamethasone (3077.5 and 1363.7 pg/g) were detected... 

Transscleral iontophoresis of steroids (dexamethasone and methylprednisolone) can be an alternative treatment for many ocular inflammations. Lam et al. [36] demonstrated high... 

Eljarrat-Binstock, E., et al. 2005. Transcorneal and transscleral iontophoresis of dexamethasone phosphate in rabbits using drug loaded hydrogel. J Control Release 106 386. 

Anderson, C.R., et al. 2003. Effects of iontophoresis current magnitude and duration on dexamethasone deposition and localized drug retention. Phys Ther 83 161. 

In ophthalmology, both trans-scleral and transcomeal dmg delivery has been studied. Drags investigated include fluorescein, tobramycin, gentamicin, ticarcillin, cefazolin, dexamethasone and ketoconazole. Iontophoresis has been found to be both safe and effective in delivering the required doses locally, at the intended site of action. Excepting for lidocaine, which has been tested in human volunteers, all the other drags have been tested in rabbits. 

Iontophoresis in the ear to relieve pain was reported by Albrecht in 1911 [47]. He used cocaine in high concentrations (20%-40%), copper electrodes, and uncontrolled high current (1.5-2 mA) on perforated tympanic membranes. Despite excellent anesthesia, many of his patients were vertiginous during and after treatment, with some patients suffering permanent loss of hearing. However, relatively recent studies have demonstrated that the use of lidocaine [48], A-acetylcysteine [49], or dexamethasone and fosfomycin [50] in iontophoresis to the ear has no adverse effects in either animal or clinical trials. Echols et al. [51] confirmed that lidocaine could be iontophoresed in the middle ear for at least 30 minutes at 1 mA without any adverse effects. 

The most common therapeutic applications of iontophoresis are topical administration of lidocaine as a local anesthetic and dexamethasone for treatment of local inflammation (lomed, Inc., Salt Lake City, Utah and Empi Corp., Minneapolis, Monnesota). In addition to these therapeutic uses, iontophoretic... 

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